Electrical connecting terminal strap



Jan. 29, 1952 s. s. s. HASSELBOHM 2,583,530

ELECTRICAL CONNECTING TERMINAL STRAP Filed Jan. 21, 1948 ljzbv Z2IZ7OJ x9. 5.5.Hass L 60m Patented Jan. 29, 1952 ELECTRICAL CONNECTING TERMINAL STRAP Sune Sigurd Sixten Hasselbohm, Hagersten, Sweden, assignor to Telefonaktiebolaget L M Ericsson, Stockholm, Sweden, a company of Sweden Application January 21, 1948, Serial No. 3,571 In Sweden January 30, 1947 2 Claims.

The present invention relates to a device for forming electrical connections between a wire and a ribbon or strap conductor. Such electrical connections must be made in most electrical apparatus, an example of which are the connections existing at the so-called soldering lugs on the relay springs. Electrical connections of the above mentioned kind have hitherto been produced by soldering, welding or by means of spring clips. This invention refers to connections of the latter type. Spring clips have hitherto usually been shaped as screw contacts, the spring tension being produced by means of a screw, or spring clips, or a combination of both. The soldering and welding of connections requires special tools, relatively large space round the contact, and professional skill. Spring clip connections do not always require the same professional skill, but are often expensive and insecure as the result of vibrations and variations of temperature, owing to the fact that several parts are comprised in the connection. One object of the invention is to produce an electric connection between a wire and a strap conductor, which is simple and cheap to produce and at the same time secure against vibrations and variations of temperature.

It is already known to make an electric connection by squeezing a wire conductor between two contact surfaces in a notch in a strap conductor, a kind of spring contact thereby being obtained, which however still has the above mentioned disadvantages. These are avoided by introducing the wire conductor into a hole in the strap conductor, and thereafter pushing the former into a slot contiguous with said hole, the width of the slot being so much smaller than the thickness of the wire conductor that the wire conductor or the contact surfaces of the slot, or both, are permanently deformed.

According to the present invention, the strap conductor is bent and its end introduced into a hole in the conductor itself, which hole serves as a tool for pressing down the wire conductor into the slot.

The invention will be described more fully with reference to the accompanying drawings, in which:

' Figure 1 is a view of the strap according to the present invention before the end portions have been bent;

Figure 2 is a sectional view on the section line 2--2 of Figure 1;

Figure 3 is a perspective view of the strap according to Figure l but with the end portions 2 bent up at right angles to the main body portion;

Figure 4 is a sectional view on the section line 4-4 of Figure 1;

Figure 5 is a perspective view of one end of the strap with a dual bend therein and showing a wire secured to the strap;

Figure 6 is a side elevation view showing two aligned wire conductors connected by the strap;

Figure 7 is a perspective view showing the main body portion of the strap inserted through spaced slots ina sheet of insulating material; and,

Figure 8 is an end view of the right end of the strap according to Figure 7 but showing the sheet of insulating material wrapped therearound.

In Fig. 1, a strap conductor, below called the strap, is shown, which strap is intended for connecting two insulated wire conductors, below called wires. The strap in this case forms a link. It is provided with. a hole 2 which connects with a slot 3 at its inner end, and nearer to the transverse center line (not shown) with a hole 4 and, still closer to the transverse center line, with an oblong or rectangular slot 6. One of the halves of such a link can naturally be used to connect a wire to an electrical apparatus of some kind, as shown in Fig. 5, the strap then being fixed to the apparatus.

According to the invention, the wire is introduced into the slot 3 and the insulation removed from the adjacent portion of the wire in the following manner. The end of the strap where the hole 2 with its slot 3 is situated is bent downward towards and pushed into the rectangular slot 6. Said slot thus serves as a kind of tool for pressing the wire into the slot 3.

A suitable way of performing said bending is shown in Figs. 3, 5 and 6. To make it simpler, the bending of one end only of the strap will be described. The bending of the other end is made complementally and in the same manner. First, the end is bent up at a point on the strap lying about midway between the bottom of the slot 3 and the rectangular slot 6. The wire 5 is thereafter introduced into the hole 2 and the strap is bent perpendicularly at about the bottom of the slot 3, the first bending operation then being continued and the end of the strap being introduced into the hole 6. The wire 5, which cannot pass through the slot 8, is thereby pressed sideways into the slot 3, the insulation surrounding said wire thus being severed and contact obtained. The bending is continued until the wire lying between the two parts of the strap blocks any further, bending. It is convenient, after the wire has been introduced into the hole 2, to bend its end around one side of the strap and reversely, so that this part of the wire will also be squeezed during the bending.

The end of the strap protruding through the effective manner by inserting'the strap through parallel spaced slots in a sheet of insulating paper after the first upward bending, as shown in Fig. '7, the paper then being bent round the connection a'fterthe bending of the ends has been accomplished, as shown in,.Fig. 8. This figure illustrates a section of the link through one of the rectangular 'slots t. The paper is suitably impregnated with an insulating and adherent substance. In orderto make it possible to introduce the end of the-strap into the oblong hole 6, the widthof saidstrap at its ends .must be smaller than at the slot 6.

,A-method according to the invention, which oiiers certain advantages .over the above procedure, but which is not usually as convenient, is the following: The-hole 2 with slot 3 in the end of the strap is. turned with the slot 3 facing the end. This. end of the strap is first introduced through the slot 6 a suflicient distance, that the hole 2 is. freeonits back-side, whereupon the wire 5 is introduced into said hole. The end of the strap is thereafter drawnback through the slot 6, the wire simultaneously being pressed into the slot 3. The thus bent part of the strap, which is formed by the reverse bending, can be squeezed against the other part of the strap so that the whole formation need-not be thicker in said case than in the casesxdescribed with referenceto the drawings.

I claim: 1. An electrical connector comprised by a pliable strip of high conductivity metal, said strip having an end portion narrower in width than the hole inwardly along the longitudinal axis of the strip, said strip being capable of being bent at an acute angle with respect to itself along a transverse line between the transverse slot and the narrow end portion, said narrow end portion being capable of being bent at right angles to the bent portion and forced into the transverse slot, whereby an insulated conductor inr serted in the hole will be forced by themain body of the strip into the longitudinal slot with the sides of the slot severing the insulation and cutting into the conductor.

2. An electrical connector comprised by a pliable strip of high conductivity metal, said strip having an end portionnarrower in width than the main body and a transverse slot adjacent its center 'atleast equal in length to the thickness of the narrower end portion, said strip also having a first conductor receiving hole intermediate the transverse slot and narrow end portion, a second conductor receiving hole in the narrow end portion of greater diameter than th'e thickness of the insulated conductor to be. re= ceived, and a longitudinal slothaving parallel sides and of lesser width than the thickness .of

the conductor itself extending from the hole inwardly along the longitudinal axis of the strip, said strip being capable of being bent at an acute anglewith respect to itself along the transverse diameter of the first-conductor receiving hole, said narrow end portion being capable of being bent at right angles to the bent portions and forced through the transverse slot, whereby an insulated conductor inserted into the second-con ductor receiving hole will be forced by the main body of the strip into the longitudinal slotwith the-sides of the slot severing the insulation and cutting into the'conductor. s SUNE SIGURD SIXTEN HASSELBQ-H-M.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

